mac80211: use nullfunc instead of probe request for connection monitoring

nullfunc frames are better for connection monitoring, because probe requests
are answered even if the AP has already dropped the connection, whereas
nullfunc frames from an unassociated station will trigger a disassoc/deauth
frame from the AP (WLAN_REASON_CLASS3_FRAME_FROM_NONASSOC_STA), which allows
the station to reconnect immediately instead of waiting until it attempts to
transmit the next unicast frame.

This only works on hardware with reliable tx ACK reporting, any other hardware
needs to fall back to the probe request method.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index ff7bc307827b..5bc0745368fe 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1265,6 +1265,8 @@ void ieee80211_send_nullfunc(struct ieee80211_local *local,
                              int powersave);
 void ieee80211_sta_rx_notify(struct ieee80211_sub_if_data *sdata,
                              struct ieee80211_hdr *hdr);
+void ieee80211_sta_tx_notify(struct ieee80211_sub_if_data *sdata,
+                             struct ieee80211_hdr *hdr);
 void ieee80211_beacon_connection_loss_work(struct work_struct *work);
 
 void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,